Chagas disease is increasingly reported in Latin American migrants who have settled in Europe. It has rarely been reported in the UK due to lack of testing and awareness.
Offer serological testing for Chagas disease to Latin American migrants:
- who are women of child-bearing age and those who are pregnant. Detection during pre-conception testing can reduce risk of vertical transmission to infants.
- with cardiac or gastrointestinal disease
- who are immunosuppressed, particularly those with HIV infection, undergoing transplantation or cancer chemotherapy
- who wish to be organ donors
Chagas disease (American trypanosomiasis) is a zoonosis caused by the flagellate protozoan parasite Trypanosoma cruzi, which:
Chagas disease has rarely been reported in the UK, and almost all cases identified have been migrants from Latin America. It is estimated that less than 5% of those infected with Trypanosoma cruzi in the UK have been identified.
Central and South America
In endemic countries, Chagas disease is primarily transmitted to people by the infected faeces of a blood-sucking triatomine bug through:
- the site of the insect bite
- another skin breach
- mucous membranes, including:
- oral or digestive mucosa
- contaminated food (less frequently)
The triatomine bug thrives under poor housing conditions (e.g. mud walls, thatched roofs). Urban and peri-urban transmission of Chagas disease can also occur in Central and South America.
The triatomine bug does not occur in the UK, so ongoing transmission from infected people by this route is not an issue. However, transmission in the UK is possible through:
- pregnancy and delivery
- laboratory accident (less frequently)
Transmission would be possible via blood transfusion and organ transplantation if blood and organ donors were not screened.
Find out about prevention and control of Chagas disease.
The acute phase of Chagas disease is unlikely to be observed in migrants to the UK. Most acute cases in endemic countries have few or no symptoms. This phase commonly lasts around 2 months immediately after infection.
The chronic phase is associated with no symptoms in the majority of patients, but 20 to 30% will go on to develop cardiac and/or digestive manifestations over the next decades.
Cardiac sequelae include:
- conduction disorders
- heart failure
- cardiac aneurysm
- secondary thromboembolism
Digestive lesions include:
Consider the possibility of Chagas disease in migrants from endemic South and Central American countries.
If the disease is suspected, request serology for Chagas disease (clotted blood sample).
If positive, and dependent upon the individual clinical presentation, refer the patient for:
- further management by the local cardiology or gastroenterology department
- definitive serological confirmation of the diagnosis and consideration of anti-parasitic treatment by an expert parasitology centre in the UK:
Two treatments are available for Chagas disease, both of which are used on a named patient basis by specialist parasitology centres, and available on request from WHO:
Treatment is generally considered to be more effective:
- for those in the acute or early chronic phase
- during reactivation if the patient becomes immunosuppressed
It is also used in cases of congenital infection.
The treatment schedule is long and is associated with frequent side effects. Once the characteristic pathology is established (e.g. dilated cardiomyopathy, mega-oesophagus), be aware that:
- antiparasitic treatment will not reverse it
- symptomatic treatment is the mainstay of management
Prevention and control
In the UK, the 2 main transmission risks are:
Reactivation of infection can occur, particularly in immunosuppressed individuals.
Pregnancy and delivery
Cost-effectiveness of screening at-risk groups has been demonstrated in Europe. However, there is currently no routine antenatal screening programme for Chagas in the UK.
Offer pre-conception screening to Latin American migrant women of child-bearing age. Pre-conception screening with treatment can also reduce the risk of congenital infection.
Offer serological testing to pregnant women who are migrants from Latin America. While treatment of Chagas during pregnancy is contraindicated, identification is important to detect and treat congenital infection. Treatment of infants is highlight effective and well tolerated. Failure to identify and treat infected infants poses risk of morbidity and premature mortality from chronic Chagas later in life.
Transfusion or transplantation
Pre-donation (blood or transplant) screening has been in place in the UK since 1999.
In the UK, a potential donor must not donate if:
- they or their mother were born in South America or Central America
- they had a blood transfusion in South America or Central America
- they lived and/or worked in rural subsistence farming communities in these countries for a continuous period of 4 weeks or more
However, a donor may donate, and the donation is used, if both of the following conditions apply:
- at least 4 months have elapsed since the last exposure
- a validated test for Trypanosoma cruzi antibody is negative
Offer screening to immunosuppressed individuals (particularly those with HIV infection, undergoing transplantation or cancer chemotherapy) as they may be at risk of reactivation of infection and associated complications.
The UK Chagas Hub provides information and resources for UK healthcare professionals, researchers, advocates and patients.
The World Health Organization (WHO) has further information on Chagas disease.
The National Travel Health Network and Centre (NaTHNaC) provides country specific travel advice.